1. Technical Field
The present invention relates generally to Bragg gratings and, more particularly, to an addressable, adaptable, semiconductive Bragg grating device.
2. Discussion
Fiber optic Bragg gratings lack a mechanism for enabling rapid modification of their characteristics such as center wavelength and spectral shape. Semiconductive Bragg gratings offer more control over center wavelength and spectral shape. A typical single mode semiconductor waveguide has a core thickness of several thousand angstroms, and an electrode placed on the top and bottom of the waveguide using a conducting substrate. A contact layer is placed on top with an interconnect metal. To vary the refractive index of the semiconductor, current is injected across the electrodes.
Although single mode semiconductive waveguides provide an advantage over fiber optic waveguides, they lack variability. As such, it is desirable to provide a semiconductive Bragg grating having a plurality of individual addressable portions along its length such that an adaption rate of several hundred MHz can be achieved.